This depends on whether you use your iPad *with* a keyboard for productivity tasks, which I do. I only remove the keyboard when I'm standing up, doing something passive like watching a movie, or where it would get in the way (e.g. using iPad whilst eating on a very small table)
Most web-sites that I use appear as the full desktop site on an iPad, and those that don't by default normally have a link to the full site somewhere on the page. No difference that I can see apart from a little less screen real-estate.